The present invention relates to an antenna for a portable cellular telephone, and more particularly to such an antenna which has shield means that limits the direction of radiation of the RF energy, preventing it from hurting the user's brain.
A portable cellular telephone uses a radio frequency energy to turn on a telephone and a switching network. The penetration of the radio frequency energy is weak to metal or building. As illustrated in FIG. 1, the frequency of the antenna 11 of the GSM system portable cellular telephone 10 is 0.930 GHZ, and the polarity curve 12 of the radio frequency energy of the antenna 11 is irregular. When the portable cellular telephone is closely attached to the ear during communication, the radio frequency energy is directly radiated from the antenna in direction toward the user's head. Therefore, the antenna must be kept away from the head at a distance when using the portable cellular telephone. However, keeping the antenna from the head at a distance affects the function of the portable cellular telephone.